Quiz: Mechanical Engineering
Exam: UPRVUNL
Topic: Miscellaneous
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 8 Minutes
Q1. Which of the following statements are correct for temperature rise in metal cutting operation?
1. it adversely affects the properties of tool material.
2. It provides in-accuracy during machining.
3. It causes dimensional changes in workpiece and affects accuracy of machining.
4. It can’t distort the accuracy of machine tool itself.
(a) 1 and 2
(b) 2 and 3
(c) 3 and 4 only
(d) 1, 2 and 3
Q2. A cantilever of length 1.2 m carries a concentrated load of 12 kN at the free end. The beam is of rectangular cross section with breadth equal to half the depth. The maximum stress due to bending is not to exceed 100 N/mm². The minimum depth of the beam should be
(a) 120 mm
(b) 60 mm
(c) 75 mm
(d) 240 mm
Q3. Flank wear occurs on the
(a) Relief face of the tool
(b) Rake face
(c) Nose of the tool
(d) Cutting edge
Q4. Mathematically, strain is defined as deformation per unit __________
(a) Length
(b) Volume
(c) Load
(d) Area
Q5. Which of the following devices complies with the Clausius statement of the second law of thermodynamics?
(a) Closed-cycle gas turbine
(b) Internal combustion engine
(c) Steam power plant
(d) Domestic refrigerator
Q6. Superheating of the steam is done at
(a) Constant temperature
(b) Constant volume
(c) Constant pressure
(d) Constant entropy
Solutions
S1. Ans. (d)
Sol. The rise of temperature of work piece and tool give rise to
(i) Early wear of tool
(ii) Dimensional in-accuracy of machined surface
(iii) Damage of surface properties of machined component.
So, statement 4 is wrong
S2. Ans.(a)
Sol. (σ_max )_per=100 MPa ;b=d/2
(σ_b )_max=(6M_max)/(bd^2 )
M_max=PL=12×10^3×1.2×10^3 Nmm
100=(6×12×10^6×1.2×2)/(d×d^2 )
d^3=12×12×12×10^3
d= 120 mm
S3. Ans.(a)
Sol. Flank wear occurs on the Relief face of the tool.
S4. Ans.(a)
Sol. Mathematically, strain is defined as deformation per unit length or we can say that it is the ratio of change in length to original length represent by ϵ.
▭(ϵ=∆l/l)
S5. Ans. (d)
S6. Ans. (c)
Sol. Superheating of the steam is done at constant pressure
